Metal spray gun



Jan. 30, 1951 w. G. SHERMAN.

METAL SPRAY GUN Filed Aug. 12, 1946 qu l Patented Jan. 30, 1951 2,539,642 METAL SPRAY GUN Wilbur G. Sherman, San Diego, Calif., assignor to Accurate Tool and Engineering Company, San Diego, Calif., a copartnershp Application August 12, 1946, Serial N0. 690,009

My invention relates to a metal spray gun and the objects of my invention are:

First, to provide a metal spray gun of this class which is particularly adapted for use in automobile body and fender work for spraying lead onto surfaces which need filling;

Second, to provide a metal spray gun of this class having a frontal shield which prevents the heating of surrounding objects by the burner of my metal spray gun;

Third, to provide a metal spray gun of this class in which a frontal shield permits the application of metal spray adjacent upholstery or the like in automobile bodies whereby much time is saved in automobile body repairing due to the time saved which would ordinarily be used in removing and replacing upholstery;

Fourth, to provide a metal spray gun of this class in which a frontal shield is provided forwardly of the burner nozzle for preventing the effects of aspiration caused by the air jet issued from the air nozzle when directedy at an acute angle to the surface of an object being sprayed;

Fifth, to provide a metal spray gun of this class in which the metal melting tube is suspended in connection with the front shield intermediate a fork portion in the frame of my metal spray gun whereby heat of the molten metal is substantially insulated from the frame handle portion of my metal spray gun;

Sixth, to provide a metal spray gun of this class in which the burner thereof provides instantaneous heat;

' Seventh, to provide a metal spray gun of this class having an adjustable mixture burner for use in connection with variable pressure fuel supplies; and

Eighth, to provide a metal spray gun of this class which is very simple and economical of construction, eliicient in operation and which will not readily deteriorate or get out of order.

With these and other objects in View as will appear hereinafter, my invention `consists of certain novel features of construction, combination and arrangement of parts and portions as will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanying drawings and to the characters of reference thereon forming a part of this application in which:

Figure l is a fragmentary top or plan view of my metal spray gun; Fig. 2 is a fragmentary sectional View thereof taken from the line 2-2 of Fig; 1, showing parts and portions in elevation to facilitate the illustration; and Fig. 3 is a reduced front end view of my metal spray gun.

7 Claims. (Cl. 91-12.2)

2 The frame I, metal melting tube 2, shield 3, burner nozzle 4, fuel valve 5, air valve 6, air nozzle l and the trigger 8 constitute the principal parts and portions of my metal spray gun. The frame I is provided with a handle portion la through which fuel and air passages Ib and I c respectively extend. The forward end of the frame I is provided with a bifurcated portion Id at the extending ends of which the shield 3 is secured thereto by the screws 3a. Supported in connection with the shield 3, intermediate the bifurcated portion of the frame I is the metal melting tube 2. This metal melting tube 2 is open at its upper end and is provided with a converging lower portion 2a terminating in an orice 2b at the bottom portion thereof, adjacent the delivery end 'la of the air nozzle 'I. It will be noted that the angular relationship of the nozzle 'I relatively to the metal melting tube 2 is slightly acute. It will be here noted that the shield 3 at its normally lower end is provided with a notch portion 3b, as shown best in Fig. 3 of the drawings, intermediate which the orifice end portion 2lb of the metal melting tube 2 is disposed a slight distance rearwardly thereof, all as shown best in Figs. 2 and 3 of the drawings. As shown in Fig. 1 of the drawings, the middle portion 3c of the shield 3 is extended rearwardly intermediate the bifurcated portions Id of the frame I. Thus, the side portions 3d of the notch portion 3a are arranged in forwardly diverging relationship to each other, allas shown best in Fig. 1 of the drawings. The air nozzle 1 is rigidly secured to the frame I in axial alignment with the hollow passage portion le in the frame I, communicating with the air valve This air valve 6 is a substantially conventional poppet valve having a stem 6a engageable with the lever portion la of the trigger 8, which is pivotally mounted in connection with the frame I by the pin 8b. The head portion 6b of the air valve 6 rests on a seat portion if in the frame I and is maintained in engagement therewith by the spring Ec held by a screw-threaded plug 6d secured in the frame I and externally removable therefrom. The inlet side of the poppet valve 6 communicates with the passage I c extending downwardly through the handle of the frame I,

all as shown best in Fig. 2 of the drawings. Communicating with the passage Ib in the han-YA dle portion Ia of the frame I, is a tubular conductor 5a communicating with the hollow bore 5b of the fuel valve 5. This fuel valve 5 is provided with a needle 5c having an externally engageable handle 5d for adjusting the same relatively to the seat portion 5g of the fuel valve 5.1

It will be noted that the casing e of the fuel valve 5 is secured by means of screw-threads 5f to the burner nozzle 4, all as shown best in Fig. 2 of the drawings. Downstream from the Valve 5 are secondary air mixing orice portions 4b in the side wall of the burner nozzle 4. Revolubly mounted on the burner nozzle 4 positioned intermediate the shoulder portion 5h of the fuel valve 5 and the upwardly extending frame portion lg of the frame l, is the air mixing valve 9.l Air mixing orices 9a in the air mixing valve 9 are arranged to regulate the volurne of air drawn in to the mixing chamber 4d through the air mixing orifices 4b. in the burner nozzle 4 and the air mixing orifices 9a when the air mixing valve 9 is rotated about the periphery of the burner nozzle 4. A hollow bore portion 4e in the burner nozzle 4 communicates with the mixing chamber 4d at one end and terminates in an enlarged bore portion 4c at the opposite end' thereof,v all" as: shown best in Fig'. 2- of the drawings.

The operation of my metal spray gun is substantially as follows:

The., operator of my metal spray gun holds, the same. by the handle portion la of the frame l.' and directs the air nozzle l toward the Work on which metal spray is being applied. Wire solder or other metal is4 positioned in the metal melting tube 2' and passes outwardly through the orifice 2li at. the bottomv thereof after being melted in the tube 2 by heat generated in the burner nozzle d and directed to the metal melting tube 2. During metal spraying operations,v the shield 3 limits the frontal, application of heat by the burner 4 to the-notch portion 3a, whereby metal spraying operations may be carried on adjacent automobile upholstery or other inflammable objects without danger of damaging the same. The heat of the. flame emitted by the burner nozzle 4 may be controlled byregulating the fuel valve 5 and the air mixing valve. 9 as desired. Intermittent spraying may be accomplished by simply pulling the trigger 8, and opening the valve 6 permitting air to flow through the. air nozzle l which atomizes the molten metal at the orifice portion 2b of the metal melting tube 2. It will be here noted that the. pattern of metal sprayr is alsol limited by the notch portion 3dy in the frontal shield 3, so that accurate control of the hot metal spray is also accomplished permitting the operator to work very close to inflammable objects. 'When the axis of the, air nozzle l is disposed at an acute angle to a surface being sprayed, an aspirati-ng effect is created upon the burner 4 tending to blow out the name therein. The shield 3 together with the relief provided by the enlarged bore portion 4c in the end of the burner nozzle 4, electively reduces the aspirating effect to such an extent that the name in the burner nozzle 4 is not adversely affected.

Though I have shown and described a particular construction, combination and arrangement of. parts and portions, I do not wish to be limited to this particular construction,l combination and arrangement, but desire to include in the scope of my invention, the construction, combination and arrangement substantially as set forth in the appended claims.

Having thus described my invention, what I claim as neva7 and desire to secure by Letters Patentis:`

l. In aV metal spray gun of the class described, the combination of a metal melting tube, a burner adapted to heat said tube, said tube having a metal outlet orifice at its normally lower end, an air nozzle directed toward the lower end of said tube, and a frontal shield forwardly of said melting tube extending parallel to the axis thereof, upwardly of said orice and having a notch p0rtion therein terminating a short distance above the lower end of said tube and diverging downwardly toward the lower end of said metal melting tube said shield at the opposite side of the axis of said orice from said burner and said air nozzle.

2. In a metal spray gun of the class described, the combination. of a. metal melting tube, a burner adapted to heat. said tube, said tube having a metal outlet. orificez at its normally lower end, an air nozzle directed toward the lower end of said tube, and a frontal shield forwardly of said metal melting tube extending parallel to the axis thereof, upwardly of said orifice and having a notch portion therein terminating ashort distance above the lower yend of said tube andl diverging down-V wardly toward the lower end ofY said metal;v Irl-.eltingr tube said shield at the opposite side of the axis, of said orice from said burner and saidv air nozzle, said frontalI shield; also.. divergingI forwardly of saidmetalmelting tube..

3. In a. metal spray gun of the class described, the combination of a. metal. melting tube, a burner adapted to heat said tube, said tube han/.ingv a.

uietaloutlet orice at itsnormally lower end, an air nozzle directed toward the lower end' of said tube, a frontal shield forwardly of'said metalv meltingl tube extending. parallel to the axis` thereon,

upwardly of said, orifice and having a notch por-- tion therein terminating a short distance above the lower end of said tube and diverging downwardly toward the lower end of said metalmelting. tuber said shield at the. opposite. side of the axis of said orifice from said burner and, said ail: nozzle, said frontal shield also diyerging forwardly of said metal melting tube, and a frame having a bifurcated portion at its forward end in c.on.V nection with said frontal shield at opposite sides of said metal melting tube.A

4. In a, metal spray gun of the class described, the combinationl of a metal melting tube, a burner adapted toy heat said tube,y said tube having a. metal. outlet orifice at its normally lower end, an air nozzle directed toward the lower end of saidtube, a` frontal shield forwardly of said metal melting tube extend-ing parallel to the axisthereof, upwardly of said orice and having a notch portion therein terminating a short distance above the lower end of said tube and diverging down-- wardly toward the lower end of said metal melting tube said shield at the opposite side et the axis, of said orifice from said burner and. said air nozzle, said frontal shieldalso cli-verging forwardly of said metal melting tube, and a frame having a bi-furcated portion at its forward end in connection with said frontal shield at opposite sides of said metal melting, tube, said metal melting tube secured to` the rear sidey of said frontal shield.

5. In a metal spray gun of the class described, the combination of a metal melting tube, a burner adapted to heat said tube said tube havingV a metal outlet orifice atits normally lower end, an air nozzle directed toward the lower end of said tube, a. frontal shield forwardly of said metal melting tube extending parallel to the axis thereof, upwardly of said orifice and having a notch portion therein terminating a short distance above the lower end of said tube and diverging down@ wardly toward the lower end cfsaidmetal melt-v ing tube said shield at the opposite side of the axis of said orice from said burner and said air nozzle, said frontal shield also diverging forwardly of said metal melting tube, and a frame having a bifurcated portion at its forward end in connection with said frontal shield at opposite sides of said metal melting tube, said metal melting tube secured to the rear side of said frontal shield, said frame having an offset portion therein intermediate the connection thereof with said frontal shield and said air nozzle, said burner nozzle supported by said offset portion intermediate said air nozzle and said bifurcated portion.

6. In a metal spray gun of the class described, the combination of a metal melting tube having a metal outlet orice therein, an air nozzle near said orifice, and a frontal shield forwardly of said metal melting tube extending laterally thereof and having a diverging notch portion exposing the orifice end portion of said metal melting tube forwardly thereof said notch portion of said shield at the opposite side of the axis of said orifice from said air nozzle, said notch portion terminating a short distance above the normally lower end of said metal melting tube and diverging downwardly.

7. In a metal spray gun of the class described.

the combination of a metal melting tube having a metal outlet orice therein, an air nozzle near said orifice, and a frontal shield forwardly of said metal melting tube extending laterally thereof and having a diverging notch portion exposing the orifice end portion of said metal melting tube forwardly thereof said notch portion of said shield at the opposite side of the axis of said orifice from said air nozzle, said notch portion terminating a short distance above the normally lower end of said metal melting tube and diverging downwardly, said frontal shield diverging forwardly and laterally of said metal melting tube.

WILBUR G, SHERMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,829,779 Benjamin Nov. 3, 1931 1,841,431 Chapin Jan. 19, 1932 v 2,058,653 Albertson Oct. 27, 1936 2,058,971 Forton Oct. 27, 1936 2,143,232 Taylor Jan. 10, 1939 2,225,168 Forton Dec. 17, 1940 

